Vehicle systems may be equipped with a plurality of vehicle control modules that receive information from vehicle electronic sensing devices and communicate regulatory information to actuators. Further, vehicle systems may be configured with vehicle data networks for data exchange and communication among the vehicle control modules, and between the vehicle control modules and associated sensors and actuators.
One example of vehicle data network is a controller area network (CAN), which is a shared serial bus system connecting the various vehicle control modules. When there is a loss of communication between the modules, information may be unavailable for arbitration and execution of vehicle actions. Therefore, vehicle systems may include an on-board diagnostic (OBD) system for monitoring vehicle operations, as well as for monitoring the vehicle network and diagnosing faults in network communication. Upon detecting loss of communication from a control module for a predetermined duration threshold (e.g., 5 seconds), the OBD system may activate a diagnostic trouble code (DTC) corresponding to the nature of fault detected.
However, the inventors herein have identified potential issues with such an approach. For example, by utilizing the predetermined duration threshold, loss of communication in the network may result in a failure in vehicle operation (due to loss of information for execution of vehicle operation) prior to the activation of a loss of communication DTC. As a result, the vehicle may enter a failure mode before the loss of communication DTC is set. Consequently, the loss of communication may not be detected leading to difficulty in diagnosing the actual cause of vehicle failure, and causing delays in problem solving. As an example, when there is a loss of communication from a fuel pump electronics module (PEM), the vehicle may stall due to lack of torque before the OBD system activates a loss of communication DTC for PEM (e.g., a U0109 code).
In one example, some of the above issues may be at least partly addressed by a method for a vehicle, comprising: determining a first time threshold for a setting a loss of communication diagnostic trouble code based on an estimated duration for loss of vehicle operation due to a loss of communication from a first module connected to a vehicle network connecting a plurality of control modules in the vehicle.
As an example, a plurality of control modules regulating one or more vehicle operations may be connected via one or more vehicular network bus for data exchange and communication. Communication from the control modules may be monitored and upon detecting a loss of communication from a control module, an estimated duration for failure of vehicle operation due to the loss of communication may be determined. Further, a time threshold for activating a loss of communication DTC may be determined based on the estimated duration for failure so as to activate the loss of communication DTC prior to occurrence of vehicle failure due to the loss of communication.
In this way, intelligent decisions for setting loss of communication DTCs may be executed by adjusting the time threshold for setting the loss of communication DTC based on the estimated duration for vehicle operation failure. As a result, loss of communication faults may be detected prior to the vehicle entering a failure mode, thereby improving loss of communication diagnosis and enabling faster problem solving.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.